Kenney said the man, who is of Palestinian origin and has legal status in Lebanon, was flown out of the country on Saturday on a plane chartered by the Canada Border Services Agency.
"After a 26-year stay in Canada, we finally succeeded in deporting this convicted terrorist killer," Kenney said at a news conference. "Mr. Mahmoud Mohammad Issa Mohammad represents just how broken Canada's immigration and refugee determination systems had become under previous governments."
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Kenney said flaws and loopholes in the system were responsible for allowing Mohammad to take advantage of Canada's generosity.
Mohammad was convicted by a Greek court of "manslaughter by negligence" after the 1968 attack on an El Al plane at the Athens airport by the Popular Front for the Liberation of Palestine, in which an Israeli man was killed.
The Greek government pardoned Mohammad in 1970 and commuted his 18-year sentence, following negotiations during a later hostage-taking aboard another plane.
Mohammad and his wife and three infant children were granted permanent residency in Canada in 1987, but an investigation by the Immigration department found he should have been inadmissible due to his conviction in the attack on the airliner, which he did not disclose in his application.
'Mockery' made of legal system
"[Mohammad] lied about his identity, he lied about not having a criminal past, he lied about not having ties to terrorist organizations," Kenney said.
Mohammad was ordered to leave Canada but filed a refugee claim. The application was denied but the legal wrangling continued for years. Mohammad was living in Burlington, Ont. His wife is a Lebanese national which is why he has travel documents for that country, Kenney said. His relatives were not deported.
"This case is almost a comedy of errors, with delays, with a system that was so bogged down in redundant process and endless appeals that it seemed to some that we would never be able to enforce the integrity of Canada's immigration system and deport this terrorist killer, " Kenney told reporters Monday.
Kenney said multiple reviews over the years determined that he would not face risk to his safety if returned to Lebanon.
Kenney said the legal proceedings have likely cost millions of dollars. The Conservative government has introduced a number of reforms to the immigration and refugee systems over the last few years, including cutting down the number of appeals that are allowed, and Kenney said this case proves why changes were needed.
"This is a cautionary tale. We should never allow a situation like this to happen again. Mr. Mohammad flagrantly violated Canada's fair immigration laws and this country's generosity," he said. "He made a mockery of our legal system."
Kenney said his department is not aware of any crimes committed by Mohammad in Canada.
An article in The Hamilton Spectator in 1988 quotes Mohammad saying he was "a freedom fighter — not a terrorist" and that his record in Canada is good and clean.
In a 1982 meeting in Beirut with the CBC's Terry Milewski, Mohammad seemed to brag about his role in the plane attack that killed an Israeli mechanic.
Kenney noted that CBSA was ready to deport Mohammad two weeks ago but that he went to a hospital. Kenney said he doesn't know the details of Mohammad's health status but that doctors from his department determined he could make the trip to Lebanon. The plane the CBSA chartered was equipped with medical equipment to ensure his safety, Kenney said.